Light-emitting device

ABSTRACT

Provided are an organometallic compound, a light-emitting device including the organometallic compound, and an electronic apparatus including the light-emitting device. The light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer disposed between the first electrode and the second electrode. The interlayer includes an emission layer. The emission layer includes a first compound which is the organometallic compound; and a second compound, a third compound, a fourth compound, or any combination thereof. The first compound, the second compound, the third compound, and the fourth compound are different from one another.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to and benefits of Korean Patent Application No. 10-2021-0034858 under 35 U.S.C. § 119, filed on Mar. 17, 2021 in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

BACKGROUND 1. Technical Field

Embodiments relate to a light-emitting device.

2. Description of the Related Art

Organic light-emitting devices (OLEDs) are self-emissive devices that have wide viewing angles, high contrast ratios, short response times, and excellent characteristics in terms of luminance, driving voltage, and response speed, compared to devices in the art.

Organic light-emitting devices may include a first electrode located on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode sequentially stacked on the first electrode. Holes provided from the first electrode may move toward the emission layer through the hole transport region, and electrons provided from the second electrode may move toward the emission layer through the electron transport region. Carriers, such as holes and electrons, recombine in the emission layer to produce excitons. These excitons transition from an excited state to a ground state to thereby generate light.

It is to be understood that this background of the technology section is, in part, intended to provide useful background for understanding the technology. However, this background of the technology section may also include ideas, concepts, or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to a corresponding effective filing date of the subject matter disclosed herein.

SUMMARY

Provided are a novel organometallic compound and a light-emitting device including the novel organometallic compound.

Additional aspects will be set forth in part in the description, which follows and, in part, will be apparent from the description, or may be learned by practice of the embodiments of the disclosure.

According to an embodiment, provided is a light-emitting device which may include a first electrode, a second electrode facing the first electrode, and an interlayer disposed between the first electrode and the second electrode, wherein the interlayer may include an emission layer, the emission layer may include a first compound which may be an organometallic compound represented by Formula 1, and a second compound which may include at least one π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group, a third compound which may be represented by Formula 11, a fourth compound which may be capable of emitting delayed fluorescence, or any combination thereof, and the first compound, the second compound, the third compound, and the fourth compound may be different from one another.

In Formula 1,

M₁ may be a transition metal,

ring A₁ to ring A₄ may each independently be a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group,

L₁ and L₂ may each independently be a single bond, *—O—*′, *—S—*′, *—C(R₅)(R₆)—*′, *—C(R₅)=*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, or *—Ge(R₅)(R₆)—*′,

L₃ may be *—N(R₇)—*′, and L₄ may be *—N(R₈)—*,

a1 and a2 may each independently be 0, 1, 2, or 3, and one of a1 and a2 may be 0, wherein, when a1 is 0, ring A₁ and ring A₂ may not be linked to each other, and when a2 is 0, ring A₂ and ring A₃ may not be linked to each other,

a3 and a4 may each independently be 1, 2, or 3,

Y₁ to Y₃ may each independently be a carbon atom (C) or a nitrogen atom (N),

Y₄ may be a nitrogen atom (N),

B₁ to B₄ may each independently be a chemical bond, *—O—*′, or *—S—*′,

R₁ to R₈ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_(10a), a C₈-C₆₀ monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_(10a), —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q)(Q₂), or —P(═S)(Q₁)(Q₂),

two neighboring substituents among R₁ to R₈ may optionally be linked to each other to form a C₅-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a),

b1 to b4 may each independently be an integer from 1 to 5, and

* and *′ each indicate a binding site to a neighboring atom.

In Formula 11,

A₅ may be O, S, N(R″₁₂), or C(R″₁₃)(R″₁₄),

m and n may each independently be an integer from 0 to 4,

R″₆ to R″₁₄ may each independently be the same as described in connection with R₁ in Formula 1, and

b″6 to b″11 may each independently be an integer from 0 to 4, and

R_(10a) may be:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group,

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or any combination thereof,

a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, or a C₆-C₆₀ arylthio group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof, or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, or a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, or any combination thereof.

In an embodiment, M₁ may be platinum (Pt), palladium (Pd), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), gold (Au), rhodium (Rh), iridium (Ir), ruthenium (Ru), rhenium (Re), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm).

In an embodiment, ring A₁ to ring A₃ may each independently be a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, an azulene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, an indenopyrimidine group, an indolopyrimidine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a benzosilolopyrimidine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a 2,3-dihydroimidazole group, a triazole group, a 2,3-dihydrotriazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a pyrazolopyridine group, a furopyrazole group, a thienopyrazole group, a benzimidazole group, a 2,3-dihydrobenzimidazole group, an imidazopyridine group, a 2,3-dihydroimidazopyridine group, a furoimidazole group, a thienoimidazole group, an imidazopyrimidine group, a 2,3-dihydroimidazopyrimidine group, an imidazopyrazine group, a 2,3-dihydroimidazopyrazine group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, or a 5,6,7,8-tetrahydroquinoline group.

In an embodiment, ring A₄ may be an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, an indenopyrimidine group, an indolopyrimidine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a benzosilolopyrimidine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, or a quinazoline group.

In an embodiment, ring A₄ may be an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, a dihydropyridine group, or a pyridine group, and ring A₁ to ring A₃ may each independently be a group represented by one of Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25), which are explained below.

In an embodiment, a1 in Formula 1 may be 0, ring A₄ may be a group represented by one of Formulae 2-2(1) to 2-2(9), which are explained below, and R₇ and R₈ may each independently be a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_(10a).

In an embodiment, the organometallic compound represented by Formula 1 may be represented by Formula 2, which is explained below.

In an embodiment, ring A₁ to ring A₃ in Formula 2 may each independently be a group represented by one of Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25), which are explained below.

In an embodiment, the first compound represented by Formula 1 may be one selected from Compounds BD1 to BD91, which are explained below.

In an embodiment, the first electrode may be an anode, the second electrode may be a cathode, and the interlayer may further include a hole transport region disposed between the first electrode and the emission layer and including a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof, and/or an electron transport region disposed between the second electrode and the emission layer and including a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

In an embodiment, the emission layer may include the fourth compound, and a weight ratio of the first compound to the fourth compound may be in a range of about 10:0.1 to about 10:1.0.

In an embodiment, the second compound may include a compound represented by Formula 10, which is explained below.

In an embodiment, the second compound represented by Formula 10 may be one selected from Compounds ETH1 to ETH84, which are explained below.

In an embodiment, the emission layer may include the second compound and the third compound, and a weight ratio of the second compound to the third compound may be in a range of about 3:7 to about 7:3.

In an embodiment, the third compound represented by Formula 11 may be one selected from Compounds HTH1 to HTH52, which are explained below.

In an embodiment, the fourth compound may be represented by Formula 12, which is explained below.

In an embodiment, the fourth compound represented by Formula 12 may be one selected from Compounds DFD1 to DFD12, which are explained below.

According to another aspect, provided is an electronic apparatus which may include the light-emitting device.

In an embodiment, the electronic apparatus may further include a thin film transistor. The thin-film transistor may include a source electrode and a drain electrode, and the first electrode of the light-emitting device may be electrically connected to at least one of the source electrode and the drain electrode of the thin-film transistor.

According to another aspect, provided is an organometallic compound which may be represented by Formula 1.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the disclosure will become more apparent by describing in detail embodiments thereof with reference to the accompanying drawings, in which:

FIG. 1 is a schematic cross-sectional view of a light-emitting device according to an embodiment;

FIG. 2 is a schematic cross-sectional view of an electronic apparatus according to an embodiment; and

FIG. 3 is a schematic cross-sectional view of an electronic apparatus according to an embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments are shown. This disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

In the drawings, the sizes, thicknesses, ratios, and dimensions of the elements may be exaggerated for ease of description and for clarity. Like numbers refer to like elements throughout.

In the description, it will be understood that when an element (or region, layer, part, etc.) is referred to as being “on”, “connected to”, or “coupled to” another element, it can be directly on, connected to, or coupled to the other element, or one or more intervening elements may be present therebetween. In a similar sense, when an element (or region, layer, part, etc.) is described as “covering” another element, it can directly cover the other element, or one or more intervening elements may be present therebetween.

In the description, when an element is “directly on,” “directly connected to,” or “directly coupled to” another element, there are no intervening elements present. For example, “directly on” may mean that two layers or two elements are disposed without an additional element such as an adhesion element therebetween.

As used herein, the expressions used in the singular such as “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. For example, “A and/or B” may be understood to mean “A, B, or A and B.” The terms “and” and “or” may be used in the conjunctive or disjunctive sense and may be understood to be equivalent to “and/or”.

In the specification and the claims, the term “at least one of” is intended to include the meaning of “at least one selected from the group of” for the purpose of its meaning and interpretation. For example, “at least one of A and B” may be understood to mean “A, B, or A and B.” When preceding a list of elements, the term, “at least one of,” modifies the entire list of elements and does not modify the individual elements of the list.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first element could be termed a second element without departing from the teachings of the disclosure. Similarly, a second element could be termed a first element, without departing from the scope of the disclosure.

The spatially relative terms “below”, “beneath”, “lower”, “above”, “upper”, or the like, may be used herein for ease of description to describe the relations between one element or component and another element or component as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, in the case where a device illustrated in the drawing is turned over, the device positioned “below” or “beneath” another device may be placed “above” another device. Accordingly, the illustrative term “below” may include both the lower and upper positions. The device may also be oriented in other directions and thus the spatially relative terms may be interpreted differently depending on the orientations.

The terms “about” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the recited value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the recited quantity (i.e., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within ±20%, ±10%, or ±5% of the stated value.

It should be understood that the terms “comprises,” “comprising,” “includes,” “including,” “have,” “having,” “contains,” “containing,” and the like are intended to specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof in the disclosure, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an ideal or excessively formal sense unless clearly defined in the specification.

A transition metal complex containing a phenylpyridine ligand in the central portion thereof as a blue phosphorescent light-emitting material and an organic light-emitting device using the same as a dopant exists in the related art, but luminescence efficiency and luminance thereof may not be sufficient. Although an organic light-emitting device using a homologous ligand-substituted transition metal complex containing a phenylimidazole ligand and an organic light-emitting device using a heterogeneous transition metal complex including imidazole carbine as a ligand exists in the related art, since blue color purity thereof is low, there is difficulty in implementing a deep blue color, and thus in implementing a full-color display of natural colors.

A heterogeneous transition metal complex containing an imidazole carbine ligand and a phenylpyridine ligand has been applied as a light-emitting material for an organic light-emitting device, but there is difficulty in implementing colors of a deep blue light-emitting device and in securing device characteristics.

Although various 4-coordinated organometallic complexes have been developed as a blue phosphor in recent years, color purity thereof may be low, or a device lifespan thereof may be short.

The related art in which a platinum-based organometallic complex incorporating a tridentate ligand as a blue or green phosphorescent dopant is used as a blue or green phosphorescent light-emitting material may lead to relatively low structural stability, compared to a case in which a complex incorporating a tetradentate ligand is used. The lifespan and efficiency of a light-emitting material may be reduced due to vibration in molecules.

According to an embodiment, a light-emitting device may include a first electrode, a second electrode facing the first electrode, and an interlayer disposed between the first electrode and the second electrode. The interlayer may include an emission layer. The emission layer may include: a first compound which is an organometallic compound represented by Formula 1; and a second compound which may include at least one 7 electron-deficient nitrogen-containing C₁-C₆₀ cyclic group, a third compound which may be represented by Formula 11, a fourth compound which may be capable of emitting delayed fluorescence, or any combination thereof.

The first compound, the second compound, the third compound, and the fourth compound may be different from one another:

In Formula 1,

M₁ may be a transition metal,

ring A₁ to ring A₄ may each independently be a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group,

L₁ and L₂ may each independently be a single bond, *—O—*′, *—S—*′, *—C(R₅)(R₆)—*′, *—C(R₅)=*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, or *—Ge(R₅)(R₆)—*′,

L₃ may be *—N(R₇)—*′, and L₄ may be *—N(R₈)—*,

a1 and a2 may each independently be 0, 1, 2, or 3, and one of a1 and a2 may be 0, wherein, when a1 is 0, ring A₁ and ring A₂ may not be linked to each other, and when a2 is 0, ring A₂ and ring A₃ may not be linked to each other,

a3 and a4 may each independently be 1, 2, or 3,

Y₁ to Y₃ may each independently be a carbon atom (C) or a nitrogen atom (N),

Y₄ may be a nitrogen atom (N),

B₁ to B₄ may each independently be a chemical bond, *—O—*′, or *—S—*′,

R₁ to R₈ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_(10a), a C₈-C₆₀ monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_(10a), —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), or —P(═S)(Q₁)(Q₂),

two neighboring substituents among R₁ to R₈ may optionally be linked to each other to form a C₅-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a),

b1 to b4 may each independently be an integer from 1 to 5,

* and *′ each indicate a binding site to a neighboring atom.

In Formula 11,

A₅ may be O, S, N(R″₁₂), or C(R″₁₃)(R″₁₄),

m and n may each independently be an integer from 0 to 4,

R″₆ to R″₁₄ are each independently the same as described in connection with R₁ in Formula 1,

b″6 to b″11 may each independently be an integer from 0 to 4, and

R_(10a) may be:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or any combination thereof;

a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, or a C₆-C₆₀ arylthio group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof; or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; or a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, or any combination thereof.

The expression “two neighboring substituents among R₁ to R₈ may optionally be linked to each other to form a C₅-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a)″ will be described in detail.

When one of two neighboring substituents is hydrogen (or deuterium), a moiety linked to hydrogen and the other neighboring substituent that is not hydrogen may be fused.

In an embodiment, when neighboring R₃ and R₅ are linked and R₃ is hydrogen, R₅ and A₃ linked to R₃ may be fused to form a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group.

In an embodiment, M₁ may be platinum (Pt), palladium (Pd), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), gold (Au), rhodium (Rh), iridium (Ir), ruthenium (Ru), rhenium (Re), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm). In an embodiment, M₁ may be platinum (Pt), palladium (Pd), nickel (Ni), copper (Cu), silver (Ag), or gold (Au).

In an embodiment, ring A₁ to ring A₃ may each independently be a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, an azulene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, an indenopyrimidine group, an indolopyrimidine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a benzosilolopyrimidine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a 2,3-dihydroimidazole group, a triazole group, a 2,3-dihydrotriazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a pyrazolopyridine group, a furopyrazole group, a thienopyrazole group, a benzimidazole group, a 2,3-dihydrobenzimidazole group, an imidazopyridine group, a 2,3-dihydroimidazopyridine group, a furoimidazole group, a thienoimidazole group, an imidazopyrimidine group, a 2,3-dihydroimidazopyrimidine group, an imidazopyrazine group, a 2,3-dihydroimidazopyrazine group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, or a 5,6,7,8-tetrahydroquinoline group.

In an embodiment, ring A₄, as a moiety including N, may be, for example, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, an indenopyrimidine group, an indolopyrimidine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a benzosilolopyrimidine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, or a quinazoline group.

In an embodiment, ring A₄ in Formula 1 may be an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, a dihydropyridine group, or a pyridine group, and

ring A₁ to ring A₃ may each independently be a group represented by one of Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25):

In Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25),

Y₁₅ may be a carbon atom (C) or a nitrogen atom (N),

X₂₁ may be N or C(R₂₁), X₂₂ may be N or C(R₂₂), X₂₃ may be N or C(R₂₃), X₂₄ may be N or C(R₂₄), X₂₅ may be N or C(R₂₅), X₂₆ may be N or C(R₂₆), X₂₇ may be N or C(R₂₇), and X₂₈ may be N or C(R₂₈),

X₂₉ may be C(R_(29a))(R_(29b)), Si(R_(29a))(R_(29b)), N(R₂₉), O, or S,

X₃₀ may be C(R_(30a))(R_(30b)), Si(R_(30a))(R_(30b)), N(R₃₀), O, or S,

R₂₁ to R₃₀ and R_(29a) to R_(30b) may each independently be the same as described in connection with R₁ in Formula 1,

* indicates a binding site to B₁, B₂, or B₃, and

*′ and *″ each indicate a binding site to a neighboring atom.

In an embodiment, in Formula 1, a1 may be 0, ring A₄ may be a group represented by one of Formulae 2-2(1) to 2-2(9), and R₇ and R₈ may each independently be a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_(10a). Y₁₅ in Formulae 2-2(1) to 2-2(9) may be a nitrogen atom (N).

For example, a3 and a4 may each be 1. In an embodiment, R₇ and R₈ may each independently be a phenyl group unsubstituted or substituted with at least one R_(10a).

In an embodiment, in Formula 1, b4 may be 2 or more, R₄ and R₇ may be linked to each other to form a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), and R₄ and R₈ may be linked each other to form a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a). For example, multiple R₄(s) may be identical to or different from each other.

In an embodiment, when the R₄(s) are all hydrogen, A₄ and R₇ may be linked to each other to form a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), and A₄ and R₈ may be linked each other to form a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a).

In an embodiment, when two of the R₄(s) are each an aryl group, and R₇ and R₈ are both hydrogen, one aryl group and N may be linked to each other and the other aryl group and N may be linked to each other to form one C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a). The aryl group may be, for example, a phenyl group.

In an embodiment, the organometallic compound represented by Formula 1 may be represented by Formula 2:

In Formula 2,

M₁, ring A₁ to ring A₃, L₁, L₂, a1, a2, Y₁ to Y₃, B₁ to B₄, R₁ to R₄, and b1 to b3 may each be the same as described in connection with Formula 1, R′₇ and R′₈ may each independently be the same as described in connection with R₁ in Formula 1, and b7 and b8 may each independently be an integer from 1 to 4.

In an embodiment, ring A₁ to ring A₃ in Formula 2 may each independently be a group represented by one of Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25).

In an embodiment, the first compound represented by Formula 1 may be one selected from Compounds BD1 to BD91:

In Compounds BD1 to BD91, D₅ indicates that five deuterium atoms are substituted at the indicated moiety. Other cases are the same.

In an embodiment, the first electrode of the light-emitting device may be an anode, the second electrode of the light-emitting device may be a cathode,

the interlayer may further include a hole transport region disposed between the first electrode and the emission layer and/or an electron transport region disposed between the emission layer and the second electrode, the hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof, and the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

In an embodiment, the emission layer may be a phosphorescent emission layer or a fluorescent emission layer.

In an embodiment, the emission layer may include a host and a dopant, and the dopant may include a first compound represented by Formula 1.

In an embodiment, the dopant may include the first compound represented by Formula 1 alone.

In an embodiment, the dopant may include a second dopant and a first dopant. The second dopant may be a phosphorescent dopant, the first dopant may be a thermally activated delayed fluorescence dopant, and the second dopant may have more intersystem crossing (ISC) occurring than emission of light.

The second dopant in the light-emitting device may have more ISC actively occurring than emission of light. Singlet excitons generated by the host may be transferred to the first dopant via ISC.

In an embodiment, about 20% to about 30% of the phosphorescent dopant, which is the second dopant, may emit light, and ISC may occur in about 80% to about 70% of the phosphorescent dopant. Singlet excitons generated by a first host, singlet excitons generated by a second host, and/or excitons generated by the first host and the second host may be transferred to the thermally activated delayed fluorescence dopant, which is the first dopant, via ISC.

In an embodiment, the dopant may include a first compound represented by Formula 1 as a second dopant and a fourth compound represented by Formula 12 as a first dopant. The second dopant may not substantially emit light, and the first dopant may emit light. In an embodiment, the first dopant may be a thermally activated delayed fluorescence dopant.

When the dopant includes the first dopant and the second dopant, a weight ratio of the second dopant to the first dopant may be in a range of 10:0.1 to 10:1.0. In an embodiment, the weight ratio of the second dopant to the first dopant may be in a range of 10:0.1 to 10:0.5. In an embodiment, the weight ratio of the second dopant to the first dopant may be in a range of 10:0.5 to 10:1.0. In consideration of the lifespans of the first dopant and the second dopant and energy transfer to the second dopant, the efficiency and lifespan of the light-emitting device may be optimized when the weight ratio is within the above range.

In an embodiment, the host may include two or more hosts. In an embodiment, the host may include an electron transport host and a hole transport host. In an embodiment, the host may include a third compound represented by Formula 11 and a fourth compound represented by Formula 12.

In an embodiment, the emission layer may be a blue emission layer.

Another aspect of the disclosure provides an electronic apparatus including a thin-film transistor and the light-emitting device. The thin-film transistor may include a source electrode, a drain electrode, an active layer, and a gate electrode, and the first electrode of the light-emitting device may be electrically connected to one of the source electrode and the drain electrode of the thin-film transistor.

The term “an interlayer” as used herein refers to a single layer and/or multiple layers disposed between the first electrode and the second electrode of an organic light-emitting device. A material included in the interlayer is not limited to an organic material.

[Description of FIG. 1]

FIG. 1 is a schematic cross-sectional view of a light-emitting device 10 according to an embodiment of the disclosure. The light-emitting device 10 includes a first electrode 110, an interlayer 130, and a second electrode 150.

Hereinafter, the structure of the light-emitting device 10 according to an embodiment and a method of manufacturing the light-emitting device 10 will be described in connection with FIG. 1.

[First Electrode 110]

In FIG. 1, a substrate may be further included under the first electrode 110 or above the second electrode 150. The substrate may be a glass substrate or a plastic substrate. In embodiments, the substrate may be a flexible substrate, and may include plastics with excellent heat resistance and durability, such as polyimide, polyethylene terephthalate (PET), polycarbonate, polyethylene napthalate, polyarylate (PAR), polyetherimide, or any combination thereof.

The first electrode 110 may be formed by, for example, depositing or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, a material for forming the first electrode 110 may be a high work function material that facilitates injection of holes.

The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, a material for forming the first electrode 110 may include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), or any combinations thereof. In embodiments, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combinations thereof may be used as a material for forming a first electrode 110.

The first electrode 110 may have a structure consisting of a single layer or a structure including multiple layers. In an embodiment, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO.

[Interlayer 130]

The interlayer 130 may be disposed on the first electrode 110. The interlayer 130 may include an emission layer.

The interlayer 130 may further include a hole transport region between the first electrode 110 and the emission layer and an electron transport region between the emission layer and the second electrode 150.

The interlayer 130 may further include, in addition to various organic materials, metal-containing compounds such as organometallic compounds, inorganic materials such as quantum dots, and the like.

In embodiments, the interlayer 130 may include two or more light-emitting units sequentially stacked between the first electrode 110 and the second electrode 150 and a charge generation layer between the two or more emitting units. When the interlayer 130 includes the two or more emitting units and the charge generation layer as described above, the light-emitting device 10 may be a tandem light-emitting device.

[Hole Transport Region in Interlayer 130]

The hole transport region may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer consisting of different materials, or a multi-layered structure including layers including different materials.

The hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof.

In an embodiment, the hole transport region may have a multi-layered structure including a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole injection layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer structure, or a hole injection layer/hole transport layer/electron blocking layer structure, wherein, in each structure, layers may be stacked from the first electrode 110 in its respective stated order, but embodiments of the disclosure are not limited thereto.

The hole transport region may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:

In Formulae 201 and 202,

L₂₀₁ to L₂₀₄ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a),

L₂₀₅ may be *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a C₁-C₂₀ alkylene group unsubstituted or substituted with at least one R_(10a), a C₂-C₂₀ alkenylene group unsubstituted or substituted with at least one R_(10a), a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a),

xa1 to xa4 may each independently be an integer from 0 to 5,

xa5 may be an integer from 1 to 10,

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a),

R₂₀₁ and R₂₀₂ may optionally be linked to each other, via a single bond, a C₁-C₅ alkylene group unsubstituted or substituted with at least one R_(10a), or a C₂-C₅ alkenylene group unsubstituted or substituted with at least one R_(10a), to form a C₈-C₆₀ polycyclic group (for example, a carbazole group or the like) unsubstituted or substituted with at least one R_(10a) (for example, Compound HT16),

R₂₀₃ and R₂₀₄ may optionally be linked to each other, via a single bond, a C₁-C₅ alkylene group unsubstituted or substituted with at least one R_(10a), or a C₂-C₅ alkenylene group unsubstituted or substituted with at least one R_(10a), to form a C₈-C₆₀ polycyclic group unsubstituted or substituted with at least one R_(10a), and

na1 may be an integer from 1 to 4.

In an embodiment, each of Formulae 201 and 202 may include at least one of groups represented by Formulae CY201 to CY217:

In Formulae CY201 to CY217, R_(10b) and R_(10c) may each independently be the same as described in connection with R_(10a), ring CY₂₀₁ to ring CY₂₀₄ may each independently be a C₃-C₂₀carbocyclic group or a C₁-C₂₀ heterocyclic group, and at least one hydrogen in Formulae CY201 to CY217 may be unsubstituted or substituted with R_(10a).

In an embodiment, ring CY₂₀₁ to ring CY₂₀₄ in Formulae CY201 to CY217 may each independently be a benzene group, a naphthalene group, a phenanthrene group, or an anthracene group.

In embodiments, each of Formulae 201 and 202 may include at least one of groups represented by Formulae CY201 to CY203.

In embodiments, Formula 201 may include at least one of groups represented by Formulae CY201 to CY203 and at least one of groups represented by Formulae CY204 to CY217.

In embodiments, in Formula 201, xa1 may be 1, R₂₀₁ may be a group represented by one of Formulae CY201 to CY203, xa2 may be 0, and R₂₀₂ may be a group represented by one of Formulae CY204 to CY207.

In embodiments, each of Formulae 201 and 202 may not include a group represented by one of Formulae CY201 to CY203.

In embodiments, each of Formulae 201 and 202 may not include a group represented by one of Formulae CY201 to CY203, and may include at least one of groups represented by Formulae CY204 to CY217.

In embodiments, each of Formulae 201 and 202 may not include a group represented by one of Formulae CY201 to CY217.

In an embodiment, the hole-transporting region may include one of Compounds HT1 to HT46, m-MTDATA, TDATA, 2-TNATA, NPB(NPD), pi-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), or any combination thereof:

A thickness of the hole transport region may be in a range of about 50 Å to about 10,000 Å. For example, the thickness of the hole transport region may be in a range of about 100 Å to about 4,000 Å. When the hole transport region includes a hole injection layer, a hole transport layer, or any combination thereof, a thickness of the hole injection layer may be in a range of about 100 Å to about 9,000 Å, and a thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å. For example, the thickness of the hole injection layer may be in a range of 100 Å to about 1,000 Å. For example, the thickness of the hole transport layer may be in a range of about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance according to a wavelength of light emitted by an emission layer, and the electron blocking layer may block the leakage of electrons from an emission layer to a hole transport region. Materials that may be included in the hole transport region may be included in the emission auxiliary layer and the electron-blocking layer.

[p-Dopant]

The hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be uniformly or non-uniformly dispersed in the hole transport region (for example, in the form of a single layer consisting of a charge-generation material).

The charge-generation material may be, for example, a p-dopant.

In an embodiment, a lowest unoccupied molecular orbital (LUMO) energy level of the p-dopant may be equal to or less than about −3.5 eV.

In an embodiment, the p-dopant may include a quinone derivative, a cyano group-containing compound, a compound containing element EL1 and element EL2, or any combination thereof.

Examples of the quinone derivative may include TCNQ and F4-TCNQ.

Examples of the cyano group-containing compound may include HAT-CN and a compound represented by Formula 221.

In Formula 221,

R₂₂₁ to R₂₂₃ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), and

at least one of R₂₂₁ to R₂₂₃ may each independently be a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each substituted with a cyano group; —F; —Cl; —Br; —I; a C₁-C₂₀ alkyl group substituted with a cyano group, —F, —Cl, —Br, —I, or any combination thereof; or any combination thereof.

In the compound containing element EL1 and element EL2, element EL1 may be a metal, a metalloid, or any combination thereof, and element EL2 may be a non-metal, a metalloid, or any combination thereof.

Examples of the metal may include an alkali metal (for example, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), etc.); an alkaline earth metal (for example, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), etc.); a transition metal (for example, titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), etc.); a post-transition metal (for example, zinc (Zn), indium (In), tin (Sn), etc.); and a lanthanide metal (for example, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc.).

Examples of the metalloid may include silicon (Si), antimony (Sb), and tellurium (Te).

Examples of the non-metal may include oxygen (O) and a halogen (for example, F, Cl, Br, I, etc.).

In an embodiment, examples of the compound containing element EL1 and element EL2 may include a metal oxide, a metal halide (for example, metal fluoride, metal chloride, metal bromide, or metal iodide), a metalloid halide (for example, metalloid fluoride, metalloid chloride, metalloid bromide, or metalloid iodide), a metal telluride, or any combination thereof.

Examples of the metal oxide may include tungsten oxide (for example, WO, W₂O₃, WO₂, WO₃, W₂O₅, etc.), vanadium oxide (for example, VO, V₂O₃, VO₂, V₂O₅, etc.), molybdenum oxide (MoO, Mo₂O₃, MoO₂, MoO₃, Mo₂O₅, etc.), and rhenium oxide (for example, ReO₃, etc.).

Examples of the metal halide may include an alkali metal halide, an alkaline earth metal halide, a transition metal halide, a post-transition metal halide, and a lanthanide metal halide.

Examples of the alkali metal halide may include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, and CsI.

Examples of the alkaline earth metal halide may include BeF₂, MgF₂, CaF₂, SrF₂, BaF₂, BeCl₂, MgCl₂, CaCl₂), SrCl₂, BaCl₂, BeBr₂, MgBr₂, CaBr₂, SrBr₂, BaBr₂, BeI₂, MgI₂, CaI₂, SrI₂, and BaI₂.

Examples of the transition metal halide may include titanium halide (for example, TiF₄, TiCl₄, TiBr₄, TiI₄, etc.), zirconium halide (for example, ZrF₄, ZrCl₄, ZrBr₄, ZrI₄, etc.), hafnium halide (for example, HfF₄, HfCl₄, HfBr₄, HfI₄, etc.), vanadium halide (for example, VF₃, VCl₃, VBr₃, VI₃, etc.), niobium halide (for example, NbF₃, NbCl₃, NbBr₃, NbI₃, etc.), tantalum halide (for example, TaF₃, TaCl₃, TaBr₃, Tab, etc.), chromium halide (for example, CrF₃, CrCl₃, CrBr₃, CrI₃, etc.), molybdenum halide (for example, MoF₃, MoCl₃, MoBr₃, MoI₃, etc.), tungsten halide (for example, WF₃, WCl₃, WBr₃, WI₃, etc.), manganese halide (for example, MnF₂, MnCl₂, MnBr₂, MnI₂, etc.), technetium halide (for example, TcF₂, TcCl₂, TcBr₂, TcI₂, etc.), rhenium halide (for example, ReF₂, ReCl₂, ReBr₂, ReI₂, etc.), iron halide (for example, FeF₂, FeCl₂, FeBr₂, FeI₂, etc.), ruthenium halide (for example, RuF₂, RuCl₂, RuBr₂, RuI₂, etc.), osmium halide (for example, OsF₂, OsCl₂, OsBr₂, OsI₂, etc.), cobalt halide (for example, CoF₂, CoCl₂, CoBr₂, CoI₂, etc.), rhodium halide (for example, RhF₂, RhCl₂, RhBr₂, RhI₂, etc.), iridium halide (for example, IrF₂, IrCl₂, IrBr₂, IrI₂, etc.), nickel halide (for example, NiF₂, NiCl₂, NiBr₂, NiI₂, etc.), palladium halide (for example, PdF₂, PdCl₂, PdBr₂, PdI₂, etc.), platinum halide (for example, PtF₂, PtCl₂, PtBr₂, PtI₂, etc.), copper halide (for example, CuF, CuCl, CuBr, CuI, etc.), silver halide (for example, AgF, AgCl, AgBr, AgI, etc.), and gold halide (for example, AuF, AuCl, AuBr, AuI, etc.).

Examples of the post-transition metal halide may include zinc halide (for example, ZnF₂, ZnCl₂, ZnBr₂, ZnI₂, etc.), indium halide (for example, InI₃, etc.), and tin halide (for example, SnI₂, etc.).

Examples of the lanthanide metal halide may include YbF, YbF₂, YbF₃, SmF₃, YbCl, YbCl₂, YbCl₃ SmCl₃, YbBr, YbBr₂, YbBr₃ SmBr₃, YbI, YbI₂, YbI₃, and SmI₃.

Examples of the metalloid halide may include antimony halide (for example, SbCl₅, etc.).

Examples of the metal telluride may include an alkali metal telluride (for example, Li₂Te, a na₂Te, K₂Te, Rb₂Te, Cs₂Te, etc.), an alkaline earth metal telluride (for example, BeTe, MgTe, CaTe, SrTe, BaTe, etc.), a transition metal telluride (for example, TiTe₂, ZrTe₂, HfTe₂, V₂Te₃, Nb₂Te₃, Ta₂Te₃, Cr₂Te₃, Mo₂Te₃, W₂Te₃, MnTe, TcTe, ReTe, FeTe, RuTe, OsTe, CoTe, RhTe, IrTe, NiTe, PdTe, PtTe, Cu₂Te, CuTe, Ag₂Te, AgTe, Au₂Te, etc.), a post-transition metal telluride (for example, ZnTe, etc.), and a lanthanide metal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, etc.).

[Emission Layer in Interlayer 130]

When the light-emitting device 10 is a full-color light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer, according to a subpixel. In embodiments, the emission layer may have a stacked structure of two or more layers of a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers may contact each other or may be separated from each other. In embodiments, the emission layer may include two or more materials of a red light-emitting material, a green light-emitting material, and a blue light-emitting material, in which the two or more materials are mixed with each other in a single layer to emit white light.

The emission layer may include a host and a dopant. The dopant may include a phosphorescent dopant, a fluorescent dopant, or any combination thereof.

The emission layer may include a first compound represented by Formula 1, according to an embodiment.

In an embodiment, the emission layer of the light-emitting device may include at least one of the first compound, the emission layer may further include a host, and an amount of the host in the emission layer may be greater than an amount of the first compound in the emission layer. In an embodiment, an amount of the first compound may be in a range of about 0.01 parts by weight to about 30 parts by weight based on 100 parts by weight of the host. In an embodiment, an amount of the first compound may be in a range of about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host.

In an embodiment, the dopant may include a first compound represented by Formula 1 (as a second dopant) and a fourth compound represented by Formula 12 (as a first dopant).

In an embodiment, the host may include a second compound represented by Formula 10 (as a first host) and a third compound represented by Formula 11 (as a second host). A weight ratio of the first host to the second host may be, for example, in a range of about 3:7 to about 7:3. In an embodiment, the weight ratio of the first host to the second host may be in a range of about 3:7 to about 5:5. When the weight ratio is within the above range, transport of holes and transport of electrons may be balanced.

An amount of the dopant (the first dopant+the second dopant) may be in a range of about 0.01 parts by weight to about 30 parts by weight based on 100 parts by weight of the host (the first host+the second host). In an embodiment, the amount of the dopant may be in a range of about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host. A weight ratio of the first dopant to the second dopant may be the same as described above.

In an embodiment, the emission layer may include the first compound, and the emission layer may emit blue light. In an embodiment, the emission layer may emit blue light having a maximum emission wavelength in a range of about 430 nm to about 485 nm. For example, the emission layer may emit blue light having a maximum emission wavelength in a range of about 440 nm to about 470 nm.

A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å. For example, the thickness of the emission layer may be in a range of about 200 Å to about 600 Å. When the thickness of the emission layer is within this range, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.

[Host]

The host may include a second compound represented by Formula 10:

In Formula 10,

ring Ar₃ to ring Ar₅ may each independently be a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group,

E may be N or C(R″₆), F may be N or C(R″₇), and G may be N or C(R″₈),

R″₃ to R″₈ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_(10a), a C₈-C₆₀ monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_(10a), —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), or —P(═S)(Q₁)(Q₂), and

b″3 to b″5 may each independently be an integer from 1 to 5.

When b″3 in Formula 10 is 2 or more, multiple R″₃(s) may be identical to or different from each other. When b″4 is 2 or more, multiple R″₄(s) may be identical to or different from each other. When b″5 is 2 or more, multiple R″₅(s) may be identical to or different from each other.

Two neighboring substituents among R″₃ to R″₈ in Formula 10 may optionally be linked to each other to form a C₅-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a).

In an embodiment, the second compound represented by Formula 10 may be one selected from Compounds ETH1 to ETH84:

In Compounds ETH1 to ETH84, D4 indicates that four deuterium atoms are substituted at the indicated moiety.

The host may include a third compound represented by Formula 11:

In Formula 11,

A₅ may be O, S, N(R″₁₂), or C(R″₁₃)(R″₁₄),

m and n may each independently be an integer from 0 to 4,

R″₆ to R″₁₄ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_(10a), a C₈-C₆₀ monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_(10a), —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), or —P(═S)(Q₁)(Q₂), and

b″6 to b″11 may each independently be an integer from 0 to 4.

When b″6 in Formula 11 is 2 or more, multiple R″₆(s) may be identical to or different from each other. When b″7 is 2 or more, multiple R″₇(s) may be identical to or different from each other. When b″8 is 2 or more, multiple R″₈(s) may be identical to or different from each other. When b″9 is 2 or more, multiple R″₉(s) may be identical to or different from each other. When b″10 is 2 or more, multiple R″₁₀(s) may be identical to or different from each other. When b″11 is 2 or more, multiple R″₁₁(s) may be identical to or different from each other.

Two neighboring substituents among R″₆ to R″₁₄ in Formula 11 may optionally be linked to each other to form a C₅-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a).

In an embodiment, the third compound represented by Formula 11 may be one selected from Compounds HTH1 to HTH52:

In Compounds HTH1 to HTH52, D₄ indicates that four deuterium atoms are substituted at the indicated moiety

[Phosphorescent Dopant]

The phosphorescent dopant may include the organometallic compound represented by Formula 1 according to an embodiment.

[Delayed Fluorescence Material]

The emission layer may include a fourth compound represented by Formula 12:

In Formula 12,

A₆ may be O, S, N(R″₂₄), or C(R″₂₅)(R″₂₆), A₇ may be O, S, N(R″₂₇), or C(R″₂₈)(R″₂₉), A₈ may be O, S, N(R″₃₀), or C(R″₃₁)(R″₃₂), and A₉ may be O, S, N(R″₃₃), or C(R″₃₄)(R″₃₅),

R″₂₀ to R″₃₅ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_(10a), a C₈-C₆₀ monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_(10a), —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), or —P(═S)(Q₁)(Q₂),

b″20 and b″21 may each independently be an integer from 0 to 3, and

b″22 and b″23 may each independently be an integer from 0 to 4.

When b″20 in Formula 12 is 2 or more, multiple R″₂₀(s) may be identical to or different from each other. When b″21 is 2 or more, multiple R″₂₁(s) may be identical to or different from each other. When b″22 is 2 or more, multiple R″₂₂(s) may be identical to or different from each other. When b″23 is 2 or more, multiple R″₂₃(s) may be identical to or different from each other.

Two neighboring substituents among R″₂₀ to R″₃₅ in Formula 12 may optionally be linked to each other to form a C₅-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a).

In an embodiment, the fourth compound represented by Formula 12 may be one of the following compounds:

In Compounds DFD1 to DFD12, D₅ indicates that five deuterium atoms are substituted at the indicated moiety.

[Electron Transport Region in Interlayer 130]

The electron transport region may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer consisting of different materials, or a multi-layered structure including layers including different materials.

The electron transport region may include a hole blocking layer, an electron control layer, an electron transport layer, an electron injection layer, or any combination thereof.

In an embodiment, the electron transport region may have an electron transport layer/electron injection layer structure, a hole blocking layer/electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, or an electron transport layer/electron injection layer structure, wherein, for each structure, constituting layers may be stacked from an emission layer in its respective stated order.

The electron transport region (for example, the hole blocking layer, the electron control layer, or the electron transport layer in the electron transport region) may include a metal-free compound including at least one π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group.

In an embodiment, the electron transport region may include a compound represented by Formula 601:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21)  [Formula 601]

In Formula 601,

Ar₆₀₁ and L₆₀₁ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a),

xe11 may be 1, 2, or 3,

xe1 may be 0, 1, 2, 3, 4, or 5,

R₆₀₁ may be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), or —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆₀₃ may each independently be the same as described in connection with Q₁,

xe21 may be 1, 2, 3, 4, or 5, and

at least one of Ar₆₀₁, L₆₀₁, and R₆₀₁ may each independently be a π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group unsubstituted or substituted with at least one R_(10a).

In an embodiment, when xe11 in Formula 601 is 2 or more, two or more of Ar₆₀₁(s) may be linked to each other via a single bond.

In embodiments, Ar₆₀₁ in Formula 601 may be a substituted or unsubstituted anthracene group.

In embodiments, the electron transport region may include a compound represented by Formula 601-1:

In Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N or C(R₆₁₆), and at least one of X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may each independently be the same as described in connection with L₆₀₁,

xe611 to xe613 may each independently be the same as described in connection with xe1,

R₆₁₁ to R₆₁₃ may each independently be the same as described in connection with R₆₀₁, and

R₆₁₄ to R₆₁₆ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a).

In an embodiment, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.

The electron transport region may include one of Compounds ETH1 to ETH84, one of Compounds ET1 to ET45, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq, TAZ, NTAZ, or any combination thereof:

A thickness of the electron transport region may be in a range of about 160 Å to about 5,000 Å. For example, the thickness of the electron transport region may be in a range of about 100 Å to about 4,000 Å. When the electron transport region includes a hole blocking layer, an electron control layer, an electron transport layer, or any combination thereof, a thickness of the hole blocking layer or the electron control layer may each independently be in a range of about 20 Å to about 1,000 Å, and a thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å. For example, the thicknesses of the hole blocking layer or the electron control layer may each independently be in a range of about 30 Å to about 300 Å. For example, the thickness of the electron transport layer may be in a range of about 150 Å to about 500 Å. When the thicknesses of the hole blocking layer, the electron control layer, the electron transport layer, and/or the electron transport layer are within these ranges, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.

The electron transport region (for example, the electron transport layer in the electron transport region) may further include, in addition to the materials described above, a metal-containing material.

The metal-containing material may include an alkali metal complex, an alkaline earth metal complex, or any combination thereof. A metal ion of the alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion, or a Cs ion, and a metal ion of an alkaline earth metal complex may be a Be ion, a Mg ion, a Ca ion, a Sr ion, or a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may include a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenylbenzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a cyclopentadiene, or any combination thereof.

In an embodiment, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (LiQ) or ET-D2:

The electron transport region may include an electron injection layer that facilitates the injection of electrons from the second electrode 150. The electron injection layer may directly contact the second electrode 150.

The electron injection layer may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer consisting of different materials, or a multi-layered structure including layers including different materials.

The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof.

The alkali metal may include Li, Na, K, Rb, Cs, or any combination thereof. The alkaline earth metal may include Mg, Ca, Sr, Ba, or any combination thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb, Gd, or any combination thereof.

The alkali metal-containing compound, the alkaline earth metal-containing compound, and the rare earth metal-containing compound may include oxides, halides (for example, fluorides, chlorides, bromides, or iodides), or tellurides of the alkali metal, the alkaline earth metal, and the rare earth metal, or any combination thereof.

The alkali metal-containing compound may include alkali metal oxides, such as Li₂O, Cs₂O, or K₂O, alkali metal halides, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, or KI, or any combination thereof. The alkaline earth metal-containing compound may include an alkaline earth metal compound, such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (x is a real number satisfying the condition of 0<x<1), Ba_(x)Ca_(1-x)O (x is a real number satisfying the condition of 0<x<1), or the like. The rare earth metal-containing compound may include YbF₃, ScF₃, Sc₂O₃, Y₂O₃, Ce₂O₃, GdF₃, TbF₃, YbI₃, ScI₃, TbI₃, or any combination thereof. In embodiments, the rare earth metal-containing compound may include a lanthanide metal telluride. Examples of the lanthanide metal telluride may include LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, La₂Te₃, Ce₂Te₃, Pr₂Te₃, Nd₂Te₃, Pm₂Te₃, Sm₂Te₃, Eu₂Te₃, Gd₂Te₃, Tb₂Te₃, Dy₂Te₃, Ho₂Te₃, Er₂Te₃, Tm₂Te₃, Yb₂Te₃, and Lu₂Te₃.

The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include one of ions of the alkali metal, ions of the alkaline earth metal, and ions of the rare earth metal and a ligand bonded to the metal ion, for example, hydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine, hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxyphenyloxadiazole, hydroxyphenylthiadiazole, hydroxyphenylpyridine, hydroxyphenyl benzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, cyclopentadiene, or any combination thereof.

The electron injection layer may consist of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof, as described above. In embodiments, the electron injection layer may further include an organic material (for example, a compound represented by Formula 601).

In an embodiment, the electron injection layer may consist of an alkali metal-containing compound (for example, an alkali metal halide); or the electron injection layer may consist of an alkali metal-containing compound (for example, an alkali metal halide), and an alkali metal, an alkaline earth metal, a rare earth metal, or any combination thereof. In an embodiment, the electron injection layer may be a KI:Yb co-deposited layer, an RbI:Yb co-deposited layer, or the like.

When the electron injection layer further includes an organic material, an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof may be homogeneously or non-homogeneously dispersed in a matrix including the organic material.

A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å. For example, the thickness of the electron injection layer may be in a range of about 3 Å to about 90 Å. When the thickness of the electron injection layer is within this range, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.

[Second Electrode 150]

The second electrode 150 may be disposed on the interlayer 130 having such a structure. The second electrode 150 may be a cathode, which is an electron injection electrode, and as the material for the second electrode 150, a metal, an alloy, an electrically conductive compound, or any combination thereof, each having a low work function, may be used.

The second electrode 150 may include lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ytterbium (Yb), silver-ytterbium (Ag—Yb), ITO, IZO, or any combination thereof. The second electrode 150 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 150 may have a single-layered structure or a multi-layered structure including two or more layers.

[Capping Layer]

A first capping layer may be located outside the first electrode 110, and/or a second capping layer may be located outside the second electrode 150. In embodiments, the light-emitting device 10 may have a structure in which the first capping layer, the first electrode 110, the interlayer 130, and the second electrode 150 are stacked in this stated order, a structure in which the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are stacked in this stated order, or a structure in which the first capping layer, the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are stacked in this stated order.

Light generated in an emission layer of the interlayer 130 of the light-emitting device 10 may be extracted toward the outside through the first electrode 110 (which may be a semi-transmissive electrode or a transmissive electrode) and through the first capping layer. Light generated in an emission layer of the interlayer 130 of the light-emitting device 10 may be extracted toward the outside through the second electrode 150 (which may be a semi-transmissive electrode or a transmissive electrode) and through the second capping layer.

The first capping layer and the second capping layer may each increase external luminescence efficiency according to the principle of constructive interference. Accordingly, the light extraction efficiency of the light-emitting device 10 may be increased, so that the luminescence efficiency of the light-emitting device 10 may be improved.

Each of the first capping layer and the second capping layer may include a material having a refractive index (at a wavelength of about 589 nm) equal to or greater than about 1.6.

The first capping layer and the second capping layer may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or an organic-inorganic composite capping layer including an organic material and an inorganic material.

At least one of the first capping layer and the second capping layer may each independently include carbocyclic compounds, heterocyclic compounds, amine group-containing compounds, porphyrin derivatives, phthalocyanine derivatives, a naphthalocyanine derivatives, alkali metal complexes, alkaline earth metal complexes, or any combination thereof. The carbocyclic compound, the heterocyclic compound, and the amine group-containing compound may each independently be optionally substituted with a substituent containing O, N, S, Se, Si, F, Cl, Br, I, or any combination thereof. In an embodiment, at least one of the first capping layer and the second capping layer may each independently include an amine group-containing compound.

In an embodiment, at least one of the first capping layer and the second capping layer may each independently include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof.

In embodiments, at least one of the first capping layer and the second capping layer may each independently include one of Compounds HT28 to HT33, one of Compounds CP1 to CP6, β-NPB, or any combination thereof:

[Electronic Apparatus]

The light-emitting device may be included in various electronic apparatuses. In an embodiment, the electronic apparatus including the light-emitting device may be a light-emitting apparatus, an authentication apparatus, or the like.

The electronic apparatus (for example, a light-emitting apparatus) may further include, in addition to the light-emitting device, a color filter, a color conversion layer, or a color filter and a color conversion layer. The color filter and/or the color conversion layer may be located in at least one traveling direction of light emitted from the light-emitting device. In an embodiment, the light emitted from the light-emitting device may be blue light or white light. The light-emitting device may be the same as described above. In an embodiment, the color conversion layer may include quantum dots. The quantum dot may be, for example, a quantum dot as described herein.

The electronic apparatus may include a first substrate. The first substrate may include subpixels, the color filter may include color filter areas respectively corresponding to the subpixels, and the color conversion layer may include color conversion areas respectively corresponding to the subpixels.

A pixel-defining film may be located among the subpixels to define each of the subpixels.

The color filter may further include color filter areas and light-shielding patterns located among the color filter areas, and the color conversion layer may include color conversion areas and light-shielding patterns located among the color conversion areas.

The color filter areas (or the color conversion areas) may include a first area emitting first-color light, a second area emitting second-color light, and/or a third area emitting third-color light, and the first-color light, the second-color light, and/or the third-color light may have different maximum emission wavelengths from one another. In an embodiment, the first-color light may be red light, the second-color light may be green light, and the third-color light may be blue light. In an embodiment, the color filter areas (or the color conversion areas) may include quantum dots. In embodiments, the first area may include a red quantum dot, the second area may include a green quantum dot, and the third area may not include a quantum dot. The quantum dot may be the same as described in the specification. Each of the first area, the second area, and/or the third area may further include a scatterer.

In an embodiment, the light-emitting device may emit first light, the first area may absorb the first light to emit first first-color light, the second area may absorb the first light to emit second first-color light, and the third area may absorb the first light to emit third first-color light. In this regard, the first first-color light, the second first-color light, and the third first-color light may have different maximum emission wavelengths from one another. In embodiments, the first light may be blue light, the first first-color light may be red light, the second first-color light may be green light, and the third first-color light may be blue light.

The electronic apparatus may further include a thin-film transistor in addition to the light-emitting device as described above. The thin-film transistor may include a source electrode, a drain electrode, and an active layer, wherein any one of the source electrode and the drain electrode may be electrically connected to any one of the first electrode and the second electrode of the light-emitting device.

The thin-film transistor may further include a gate electrode, a gate insulating film, or the like.

The active layer may include crystalline silicon, amorphous silicon, organic semiconductor, oxide semiconductor, or the like.

The electronic apparatus may further include a sealing portion for sealing the light-emitting device. The sealing portion and/or the color conversion layer may be located between the color filter and the light-emitting device. The sealing portion may allow light from the light-emitting device to be extracted to the outside, and may simultaneously prevent ambient air and moisture from penetrating into the light-emitting device. The sealing portion may be a sealing substrate including a transparent glass substrate or a plastic substrate. The sealing portion may be a thin-film encapsulation layer including at least one of an organic layer and/or an inorganic layer. When the sealing portion is a thin film encapsulation layer, the electronic apparatus may be flexible.

Various functional layers may be additionally located on the sealing portion, in addition to the color filter and/or the color conversion layer, according to the use of the electronic apparatus. Examples of the functional layers may include a touch screen layer, a polarizing layer, an authentication apparatus, and the like. The touch screen layer may be a pressure-sensitive touch screen layer, a capacitive touch screen layer, or an infrared touch screen layer. The authentication apparatus may be, for example, a biometric authentication apparatus that authenticates an individual by using biometric information of a living body (for example, fingertips, pupils, etc.).

The authentication apparatus may further include, in addition to the light-emitting device, a biometric information collector.

The electronic apparatus may be applied to various displays, such as light sources, lighting, personal computers (for example, a mobile personal computer), mobile phones, digital cameras, electronic organizers, electronic dictionaries, electronic game machines, medical instruments (for example, electronic thermometers, sphygmomanometers, blood glucose meters, pulse measurement devices, pulse wave measurement devices, electrocardiogram displays, ultrasonic diagnostic devices, or endoscope displays), fish finders, various measuring instruments, meters (for example, meters for a vehicle, an aircraft, and a vessel), projectors, and the like.

[Description of FIGS. 2 and 3]

FIG. 2 is a schematic cross-sectional view of an electronic apparatus according to an embodiment of the disclosure.

The electronic apparatus of FIG. 2 includes a substrate 100, a thin-film transistor (TFT), a light-emitting device, and an encapsulation portion 300 that seals the light-emitting device.

The substrate 100 may be a flexible substrate, a glass substrate, or a metal substrate. A buffer layer 210 may be located on the substrate 100. The buffer layer 210 may prevent penetration of impurities through the substrate 100 and may provide a flat surface on the substrate 100.

A TFT may be located on the buffer layer 210. The TFT may include an active layer 220, a gate electrode 240, a source electrode 260, and a drain electrode 270.

The active layer 220 may include an inorganic semiconductor such as silicon or polysilicon, an organic semiconductor, or an oxide semiconductor, and may include a source region, a drain region, and a channel region.

A gate insulating film 230 for insulating the active layer 220 from the gate electrode 240 may be located on the active layer 220, and the gate electrode 240 may be located on the gate insulating film 230.

An interlayer insulating film 250 may be located on the gate electrode 240. The interlayer insulating film 250 may be located between the gate electrode 240 and the source electrode 260 to insulate the gate electrode 240 from the source electrode 260 and between the gate electrode 240 and the drain electrode 270 to insulate the gate electrode 240 from the drain electrode 270.

The source electrode 260 and the drain electrode 270 may be located on the interlayer insulating film 250. The interlayer insulating film 250 and the gate insulating film 230 may be formed to expose the source region and the drain region of the active layer 220, and the source electrode 260 and the drain electrode 270 may be in contact with the exposed portions of the source region and the drain region of the active layer 220.

The TFT is electrically connected to a light-emitting device to drive the light-emitting device, and is covered by a passivation layer 280. The passivation layer 280 may include an inorganic insulating film, an organic insulating film, or any combination thereof. A light-emitting device is provided on the passivation layer 280. The light-emitting device may include a first electrode 110, an interlayer 130, and a second electrode 150.

The first electrode 110 may be located on the passivation layer 280. The passivation layer 280 may not completely cover the drain electrode 270 and may expose a portion of the drain electrode 270, and the first electrode 110 may be electrically connected to the exposed portion of the drain electrode 270.

A pixel defining layer 290 containing an insulating material may be located on the first electrode 110. The pixel defining layer 290 may expose a portion of the first electrode 110, and the interlayer 130 may be formed in the exposed portion of the first electrode 110. The pixel defining layer 290 may be a polyimide or polyacrylic organic film. Although not shown in FIG. 2, at least some layers of the interlayer 130 may extend beyond the upper portion of the pixel defining layer 290 to be provided in the form of a common layer.

The second electrode 150 may be located on the interlayer 130, and a capping layer 170 may be additionally formed on the second electrode 150. The capping layer 170 may be formed to cover the second electrode 150.

The encapsulation portion 300 may be located on the capping layer 170. The encapsulation portion 300 may be located on a light-emitting device to protect the light-emitting device from moisture and/or oxygen. The encapsulation portion 300 may include: an inorganic film including silicon nitride (SiNx), silicon oxide (SiOx), indium tin oxide, indium zinc oxide, or any combination thereof; an organic film including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acrylic resin (for example, polymethyl methacrylate, polyacrylic acid, or the like), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), or the like), or any combination thereof; or any combination of the inorganic film and the organic film.

FIG. 3 is a schematic cross-sectional view of an electronic apparatus according to an embodiment of the disclosure.

The light-emitting apparatus of FIG. 3 is the same as the light-emitting apparatus of FIG. 2, except that a light-shielding pattern 500 and a functional region 400 are additionally located on the encapsulation portion 300. The functional region 400 may be a color filter area, a color conversion area, or a combination of the color filter area and the color conversion area. In an embodiment, the light-emitting device included in the electronic apparatus of FIG. 3 may be a tandem light-emitting device.

[Manufacture Method]

Respective layers included in the hole transport region, the emission layer, and respective layers included in the electron transport region may be formed in a certain region by using one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging.

When respective layers included in the hole transport region, the emission layer, and respective layers included in the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10⁻⁸ torr to about 10⁻³ torr, and a deposition speed of about 0.01 Å/sec to about 100 Å/sec, depending on a material to be included in a layer to be formed and the structure of a layer to be formed.

Definitions of Terms

The term “C₃-C₆₀ carbocyclic group” as used herein may be a cyclic group consisting of carbon only as a ring-forming atom and having 3 to 60 carbon atoms, and the term “C₁-C₆₀ heterocyclic group” as used herein may be a cyclic group that has 1 to 60 carbon atoms and further has, in addition to carbon, at least one heteroatom as a ring-forming atom. The C₃-C₆₀ carbocyclic group and the C₁-C₆₀ heterocyclic group may each be a monocyclic group consisting of one ring or a polycyclic group in which two or more rings are condensed with each other. In an embodiment, a C₁-C₆₀ heterocyclic group may have 3 to 61 ring-forming atoms.

The term “cyclic group” as used herein may include the C₃-C₆₀ carbocyclic group and the C₁-C₆₀ heterocyclic group.

The term “π electron-rich C₃-C₆₀ cyclic group” as used herein may be a cyclic group that has 3 to 60 carbon atoms and may not include *—N=*′ as a ring-forming moiety, and the term “π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group” as used herein may be a heterocyclic group that has 1 to 60 carbon atoms and may include *—N=*′ as a ring-forming moiety.

In embodiments,

the C₃-C₆₀ carbocyclic group may be a T1 group or a condensed cyclic group in which two or more T1 groups are condensed with each other (for example, a cyclopentadiene group, an adamantane group, a norbornane group, a benzene group, a pentalene group, a naphthalene group, an azulene group, an indacene group, an acenaphthylene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a perylene group, a pentaphene group, a heptalene group, a naphthacene group, a picene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, an indene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, an indenophenanthrene group, or an indenoanthracene group),

the C₁-C₆₀ heterocyclic group may be a T2 group, a condensed cyclic group in which two or more T2 groups are condensed with each other, or a condensed cyclic group in which at least one T2 group and at least one T1 group are condensed with each other (for example, a pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzoisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, etc.),

the π electron-rich C₃-C₆₀ cyclic group may be a T1 group, a condensed cyclic group in which two or more T1 groups are condensed with each other, a T3 group, a condensed cyclic group in which two or more T3 groups are condensed with each other, or a condensed cyclic group in which at least one T3 group and at least one T1 group are condensed with each other (for example, the C₃-C₆₀ carbocyclic group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, etc.),

the π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group may be a T4 group, a condensed cyclic group in which two or more T4 groups are condensed with each other, a condensed cyclic group in which at least one T4 group and at least one T1 group are condensed with each other, a condensed cyclic group in which at least one T4 group and at least one T3 group are condensed with each other, or a condensed cyclic group in which at least one T4 group, at least one T1 group, and at least one T3 group are condensed with one another (for example, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzoisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, etc.),

wherein the T1 group may be a cyclopropane group, a cyclobutane group, a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclooctane group, a cyclobutene group, a cyclopentene group, a cyclopentadiene group, a cyclohexene group, a cyclohexadiene group, a cycloheptene group, an adamantane group, a norbornane (or a bicyclo[2.2.1]heptane) group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.2]octane group, or a benzene group,

the T2 group may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a tetrazine group, a pyrrolidine group, an imidazolidine group, a dihydropyrrole group, a piperidine group, a tetrahydropyridine group, a dihydropyridine group, a hexahydropyrimidine group, a tetrahydropyrimidine group, a dihydropyrimidine group, a piperazine group, a tetrahydropyrazine group, a dihydropyrazine group, a tetrahydropyridazine group, or a dihydropyridazine group,

the T3 group may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, or a borole group, and

the T4 group may be a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, or a tetrazine group.

The terms “cyclic group,” “C₃-C₆₀ carbocyclic group,” “C₁-C₆₀ heterocyclic group,” “π electron-rich C₃-C₆₀ cyclic group,” or “π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group” as used herein may be a group condensed to any cyclic group or a polyvalent group (for example, a divalent group, a trivalent group, a tetravalent group, etc.), depending on the structure of a formula in connection with which the terms are used. In an embodiment, “a benzene group” may be a benzo group, a phenyl group, a phenylene group, or the like, which may be easily understood by one of ordinary skill in the art according to the structure of a formula including the “benzene group.”

Examples of the monovalent C₃-C₆₀ carbocyclic group and the monovalent C₁-C₆₀ heterocyclic group may include a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, and examples of the divalent C₃-C₆₀ carbocyclic group and the monovalent C₁-C₆₀ heterocyclic group may include a C₃-C₁₀cycloalkylene group, a C₁-C₁₀ heterocycloalkylene group, a C₃-C₁₀ cycloalkenylene group, a C₁-C₁₀ heterocycloalkenylene group, a C₆-C₆₀ arylene group, a C₁-C₆₀ heteroarylene group, a divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group.

The term “C₁-C₆₀ alkyl group” as used herein may be a linear or branched aliphatic hydrocarbon monovalent group that has 1 to 60 carbon atoms, and examples thereof may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decyl group. The term “C₁-C₆₀ alkylene group” as used herein may be a divalent group having a same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group” as used herein may be a monovalent hydrocarbon group having at least one carbon-carbon double bond in the middle or at the terminus of the C₂-C₆₀ alkyl group, and examples thereof may include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group” as used herein may be a divalent group having a same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein may be a monovalent hydrocarbon group having at least one carbon-carbon triple bond in the middle or at the terminus of the C₂-C₆₀ alkyl group, and examples thereof may include an ethynyl group and a propynyl group. The term “C₂-C₆₀ alkynylene group” as used herein may be a divalent group having a same structure as the C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as used herein may be a monovalent group represented by —O(A₁₀₁) (wherein A₁₀₁ is a C₁-C₆₀ alkyl group), and examples thereof may include a methoxy group, an ethoxy group, and an isopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as used herein may be a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and examples thereof may include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group (or bicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, and a bicyclo[2.2.2]octyl group. The term “C₃-C₁₀ cycloalkylene group” as used herein may be a divalent group having a same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein may be a monovalent cyclic group that further includes, in addition to a carbon atom, at least one heteroatom as a ring-forming atom and has 1 to 10 carbon atoms, and examples thereof may include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group” as used herein may be a divalent group having a same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein may be a monovalent cyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and examples thereof may include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” as used herein may be a divalent group having a same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein may be a monovalent cyclic group that has, in addition to a carbon atom, at least one heteroatom as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond in the cyclic structure thereof. Examples of the C₁-C₁₀ heterocycloalkenyl group may include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylene group” as used herein may be a divalent group having a same structure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein may be a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms, and the term “C₆-C₆₀ arylene group” as used herein may be a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Examples of the C₆-C₆₀ aryl group may include a phenyl group, a pentalenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a heptalenyl group, a naphthacenyl group, a picenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, and an ovalenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene group each include two or more rings, the rings may be condensed with each other.

The term “C₁-C₆₀ heteroaryl group” as used herein may be a monovalent group having a heterocyclic aromatic system that has, in addition to a carbon atom, at least one heteroatom as a ring-forming atom, and 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group” as used herein may be a divalent group having a heterocyclic aromatic system that has, in addition to a carbon atom, at least one heteroatom as a ring-forming atom, and 1 to 60 carbon atoms. Examples of the C₁-C₆₀ heteroaryl group may include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a benzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinyl group, a phthalazinyl group, and a naphthyridinyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group each include two or more rings, the rings may be condensed with each other.

The term “monovalent non-aromatic condensed polycyclic group” as used herein may be a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed polycyclic group may include an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, and an indeno anthracenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein may be a divalent group having a same structure as a monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein may be a monovalent group (for example, having 1 to 60 carbon atoms) having two or more rings condensed to each other, at least one heteroatom other than carbon atoms, as a ring-forming atom, and non-aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed heteropolycyclic group may include a pyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group, a benzoindolyl group, a naphtho indolyl group, an isoindolyl group, a benzoisoindolyl group, a naphthoisoindolyl group, a benzosilolyl group, a benzothiophenyl group, a benzofuranyl group, a carbazolyl group, a dibenzosilolyl group, a dibenzothiophenyl group, a dibenzofuranyl group, an azacarbazolyl group, an azafluorenyl group, an azadibenzosilolyl group, an azadibenzothiophenyl group, an azadibenzofuranyl group, a pyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group, an oxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzopyrazolyl group, a benzimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a benzoxadiazolyl group, a benzothiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an imidazotriazinyl group, an imidazopyrazinyl group, an imidazopyridazinyl group, an indenocarbazolyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a benzosilolocarbazolyl group, a benzoindolocarbazolyl group, a benzocarbazolyl group, a benzonaphthofuranyl group, a benzonaphthothiophenyl group, a benzonaphthosilolyl group, a benzofurodibenzofuranyl group, a benzofurodibenzothiophenyl group, and a benzothienodibenzothiophenyl group. The term “divalent non-aromatic heterocondensed polycyclic group” as used herein may be a divalent group having a same structure as a monovalent non-aromatic heterocondensed polycyclic group.

The term “C₆-C₆₀ aryloxy group” as used herein may be represented by —O(A₁₀₂) (wherein A₁₀₂ is a C₆-C₆₀ aryl group), and the term “C₆-C₆₀ arylthio group” as used herein may be represented by —S(A₁₀₃) (wherein A₁₀₃ is a C₆-C₆₀ aryl group).

The term “C₇-C₆₀ aryl alkyl group” used herein may be represented by -(A₁₀₄)(A₁₀₅) (wherein A₁₀₄ may be a C₁-C₅₄ alkylene group, and A₁₀₅ may be a C₆-C₅₉ aryl group), and the term “C₂-C₆₀ heteroaryl alkyl group” as used herein may be represented by -(A₁₀₆)(A₁₀₇) (wherein A₁₀₆ may be a C₁-C₅₉ alkylene group, and A₁₀₇ may be a C₁-C₅₉ heteroaryl group).

The term “R_(10a)” as used herein may be:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, a C₂-C₆₀ heteroaryl alkyl group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or any combination thereof;

a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, or a C₂-C₆₀ heteroaryl alkyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, a C₂-C₆₀ heteroaryl alkyl group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof; or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂).

Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ used herein may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, or any combination thereof; a C₇-C₆₀ aryl alkyl group; or a C₂-C₆₀ heteroaryl alkyl group.

The term “heteroatom” as used herein may be any atom other than a carbon atom or a hydrogen atom. Examples of the heteroatom may include O, S, N, P, Si, B, Ge, Se, or any combination thereof.

The term “the third-row transition metal” as used herein may include hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), or gold (Au).

The term “Ph” as used herein refers to a phenyl group, the term “Me” as used herein refers to a methyl group, the term “Et” as used herein refers to an ethyl group, the term “ter-Bu” or “Bu^(t)” as used herein refers to a tert-butyl group, and the term “OMe” as used herein refers to a methoxy group.

The term “biphenyl group” as used herein may be “a phenyl group substituted with a phenyl group.” For example, the “biphenyl group” may be a substituted phenyl group having a C₆-C₆₀ aryl group as a substituent.

The term “terphenyl group” as used herein may be “a phenyl group substituted with a biphenyl group”. For example, the “terphenyl group” may be a substituted phenyl group having, as a substituent, a C₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group.

The number of carbon atoms in this substituent definition section is an example only. In an embodiment, the maximum carbon number of 60 in the C₁-C₆₀ alkyl group is an example, and the definition of the alkyl group is equally applied to a C₁-C₂₀ alkyl group. In an embodiment, the minimum carbon number of 12 in the C₁₂-C₆₀ heteroaryl group is an example, and the definition of the heteroaryl group is equally applied. Other cases are the same.

In the description, * and *′ and *″ as used herein, unless defined otherwise, each represent a binding site to a neighboring atom in a corresponding formula or moiety.

Hereinafter, a compound according to embodiments and a light-emitting device according to embodiments will be described in detail with reference to Synthesis Examples and Examples. The wording “B was used instead of A” used in describing Synthesis Examples refers to that an identical molar equivalent of B was used in place of A.

EXAMPLES Synthesis Example 1: Synthesis of Compound BD1

1) Synthesis of Intermediate [BD1-A]

1-bromo-3-fluorobenzene (1.0 eq), imidazole (1.3 eq), and K₃PO₄ (2.0 eq) were added to a reaction vessel and suspended in DMF (0.25 M). The reaction mixture was heated and stirred at 160° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD1-A] (yield of 85%).

2) Synthesis of Intermediate [BD1-B]

Intermediate [BD1-A] (1.0 eq), 5,7-dihydropyrido[2,3-b:6,5-b′]diindole (CAS No. 950487-75-9) (1.2 eq), K₂CO₃ (2.0 eq), CuI (0.1 eq), and 1,10-phenanthroline (0.1 eq) were added to a reaction vessel and suspended in DMF (0.25 M). The reaction mixture was heated and stirred at 160° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD1-B] (yield of 62%).

3) Synthesis of Intermediate [BD1-C]

Intermediate [BD1-B] (1.0 eq), bromobenzene (1.2 eq), K₃PO₄ (2.0 eq), CuI (0.1 eq), and 1,10-phenanthroline (0.1 eq) were added to a reaction vessel and suspended in DMF (0.25 M). The reaction mixture was heated and stirred at 160° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD1-C](yield of 76%).

4) Synthesis of Intermediate [BD1-D]

Intermediate [BD1-C] (1.0 eq) and iodomethane (10.0 eq) were added to a reaction vessel and suspended in toluene (0.1 M). The reaction mixture was heated and stirred at 110° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was dried using magnesium sulfate, and the solvent was removed therefrom to obtain Intermediate [BD1-D] (yield of 91%).

5) Synthesis of Intermediate [BD1-E]

Intermediate [BD1-D] (1.0 eq) was added to a reaction vessel and suspended in a mixed solution of methanol and distilled water at a ratio of 2:1. When the mixture was sufficiently dissolved, ammonium hexafluorophosphate (1.1 eq) was slowly added thereto, and the reaction solution was stirred at room temperature for 24 hours. After completion of the reaction, the resulting solid was filtered and washed with diethyl ether. The washed solid was dried to obtain Intermediate [BD1-E] (yield of 93%).

6) Synthesis of Compound BD1

Intermediate [BD1-E] (1.0 eq), dichloro(1,5-cyclooctadiene)platinum (1.1 eq), and sodium acetate (3.0 eq) were suspended in 1,4-dioxane (0.1 M). The reaction mixture was heated and stirred at 120° C. for 72 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Compound BD1 (yield of 33%).

Synthesis Example 2: Synthesis of Compound BD5

Compound BD5 was synthesized in the same manner as in Synthesis Example of Compound BD1 except that 12-p-anisole 5,7-dihydropyrido[2,3-b:6,5-b′]diindoles was used instead of 5,7-dihydropyrido[2,3-b:6,5-b′]diindoles.

Synthesis Example 3: Synthesis of Compound BD27

1) Synthesis of Intermediate [BD27-A]

3,5-dichloropyridine (1.0 eq), (5-methyl-2-nitrophenyl)boronic acid (3.0 eq), and NaOH (3.0 eq) were added to a reaction vessel and suspended in THF/H₂O at a ratio of 2:1 (0.1 M). Pd(PPh₃)₄ (0.05 eq) was added thereto at 40° C., and the reaction mixture was heated and stirred at 80° C. for 12 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and methylene chloride. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD27-A] (yield of 65%).

2) Synthesis of Intermediate [BD27-B]

Intermediate [BD27-A] (1.0 eq) and PPh₃ (2.5 eq) were added to a reaction vessel and suspended in 1,2-dichlorobenzene (0.25 M). The reaction mixture was stirred 12 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and dichloromethane. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD27-B] (yield of 45%).

3) Synthesis of Intermediate [BD27-C]

Intermediate [BD27-B] (1.2 eq), bromobenzene (1.0 eq), K₃PO₄ (2.0 eq), CuI (0.1 eq), and 1,10-phenanthroline (0.1 eq) were added to a reaction vessel and suspended in DMF (0.25 M). The reaction mixture was heated and stirred at 160° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD27-C](yield of 66%).

4) Synthesis of Intermediate [BD27-D]

Intermediate [BD27-C] (1.0 eq), 1-(3-bromophenyl)-1H-benzo[d]imidazole (1.2 eq), K₃PO₄ (2.0 eq), CuI (0.1 eq), and 1,10-phenanthroline (0.1 eq) were added to a reaction vessel and suspended in DMF (0.25 M). The reaction mixture was heated and stirred at 160° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD27-D] (yield of 84%).

5) Synthesis of Intermediate [BD27-E]

Intermediate [BD27-D] (1.0 eq) and iodomethane (10.0 eq) were added to a reaction vessel and suspended in toluene (0.1 M). The reaction mixture was heated and stirred at 110° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was dried using magnesium sulfate, and the solvent was removed therefrom to obtain Intermediate [BD27-E] (yield of 94%).

6) Synthesis of Intermediate [BD27-F]

Intermediate [BD27-F] (yield of 97%) was obtained in the same manner as in Synthesis Example of Intermediate [BD1-E], except that Intermediate [BD27-E] was used instead of Intermediate [BD1-D].

7) Synthesis of Compound BD27

Compound BD27 (yield of 31%) was obtained in the same manner as in Synthesis Example of Compound BD1, except that Intermediate [BD27-F] was used instead of Intermediate [BD1-E].

Synthesis Example 4: Synthesis of Compound BD36

1) Synthesis of Intermediate [BD36-A]

Intermediate [BD36-A] (yield of 58%) was obtained in the same manner as in Synthesis Example of Intermediate [BD1-B], except that 2-bromo-1-(2,6-dimethylphenyl)-1H-imidazole-methane (CAS No. 1267555-81-6) was used instead of Intermediate [BD1-A].

2) Synthesis of Intermediate [BD36-B]

Intermediate [BD36-A] (1.0 eq), 1-bromo-3-fluorobenzene (1.2 eq), and K₃PO₄ (2.0 eq) were added to a reaction vessel and suspended in DMF (0.25 M). The reaction mixture was heated and stirred at 160° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD36-B] (yield of 65%).

3) Synthesis of Intermediate [BD36-C]

Intermediate [BD36-B] (1.0 eq), (3-(tert-butyl)phenyl)boronic acid (1.2 eq), Pd(PPh₃)₄ (0.1 eq), and K₂CO₃ (2.0 eq) were added to a reaction vessel and suspended in dioxane:H₂O at a ratio of 3:1 (0.1 M). The reaction mixture was heated and stirred at 160° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD36-C] (yield of 74%).

4) Synthesis of Compound BD36

Intermediate [BD36-C] (1.0 eq), potassium tetrachloroplatinate (1.1 eq), and tetrabutylammonium bromide (0.1 eq) were suspended in AcOH (0.03 M). The reaction mixture was heated and stirred at 110° C. for 72 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and dichloromethane. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Compound BD36 (yield of 29%).

Synthesis Example 5: Synthesis of Compound BD46

1) Synthesis of Intermediate [BD46-A]

Intermediate [BD46-A] (yield of 62%) was obtained in the same manner as in Synthesis Example of Intermediate [BD1-B], except that bromobenzene was used instead of Intermediate [BD1-A].

2) Synthesis of Intermediate [BD46-B]

Intermediate [BD46-A] (1.0 eq), 2-(3-fluorophenyl)pyridine (1.2 eq), and K₃PO₄ (2.0 eq) were added to a reaction vessel and suspended in DMF (0.25 M). The reaction mixture was heated and stirred at 160° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD46-B] (yield of 70%).

3) Synthesis of Compound BD46

Compound BD46 (yield of 35%) was obtained in the same manner as in Synthesis Example of Compound BD1, except that Intermediate [BD46-B] was used instead of Intermediate [BD1-E].

Synthesis Example 6: Synthesis of Compound BD65

1) Synthesis of Intermediate [BD65-A]

Bromobenzene (1.0 eq), 12-(4-methoxyphenyl)-5,7-dihydropyrido[2,3-b:6,5-b′]diindole (CAS No. 1415641-42-7) (1.2 eq), K₂CO₃ (2.0 eq), CuI (0.1 eq), and 1,10-phenanthroline (0.1 eq) were added to a reaction vessel and suspended in DMF (0.25 M). The reaction mixture was heated and stirred at 160° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD65-A] (yield of 69%).

2) Synthesis of Intermediate [BD65-B]

Intermediate [BD65-A](1.0 eq), 2-fluoro-6-phenylpyridine (1.2 eq), K₃PO₄ (2.0 eq) were added to a reaction vessel and suspended in DMF (0.25 M). The reaction mixture was heated and stirred at 160° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD65-B] (yield of 72%).

3) Synthesis of Compound BD65

Compound BD65 (yield of 37%) was obtained in the same manner as in Synthesis Example of Compound BD1, except that Intermediate [BD65-B] was used instead of Intermediate [BD1-E].

Synthesis Example 7: Synthesis of Compound BD80

1) Synthesis of Intermediate [BD80-A]

Intermediate [BD80-A] (yield of 56%) was obtained in the same manner as in Synthesis Example of Intermediate [BD65-A], except that 2-bromopyridine was used instead of bromobenzene.

2) Synthesis of Intermediate [BD80-B]

Intermediate [BD80-A] (1.0 eq), 3-fluoro-1,1′-biphenyl (1.2 eq), and K₃PO₄ (2.0 eq) were added to a reaction vessel and suspended in DMF (0.25 M). The reaction mixture was heated and stirred at 160° C. for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and extracted with distilled water and ethyl acetate. An organic layer extracted therefrom was washed with a saturated NaCl aqueous solution and dried using magnesium sulfate. A residue obtained by removing the solvent therefrom was separated by column chromatography to obtain Intermediate [BD80-B] (yield of 75%).

3) Synthesis of Compound BD80

Compound BD80 (yield of 32%) was obtained in the same manner as in Synthesis Example of Compound BD1, except that Intermediate [BD80-B] was used instead of Intermediate [BD1-E].

¹H NMR and MS/FAB of the compounds synthesized according to Synthesis Examples are shown in Table 1.

Synthesis methods for other compounds than the compounds shown in Table 1 may be easily recognized by those skilled in the technical field by referring to the synthesis paths and source material materials described above.

TABLE 1 MS/FAB Compound ¹H NMR (CDCl₃ , 400 MHz) found calc. BD1 3.71(s, 3H), 7.16(t, 2H), 7.27(d, 1H), 7.31-7.35(m, 3H), 682.13 682.65 7.44-7.49(m, 3H), 7.58(d, 1H), 7.70-7.72(m, 3H), 7.75(s, 1H), 7.95(d, 2H), 8.53(d, 2H) BD5 3.70(s, 3H), 3.81(s, 3H), 7.00(d, 2H), 7.15(t, 2H), 788.20 788.77 7.26(d, 1H), 7.30-7.34(m, 3H), 7.44(d, 1H), 7.47(d, 1H), , 7.49(d, 1H), 7.56(d, 1H), 7.70-7.74(m, 5H), 7.94(d, 2H), 8.54(d, 2H) BD27 8.80(s, 2H), 8.56(d, 1H), 7.89-7.91 (m, 3H), 7.74(m, 2H), 819.27 819.89 7.64(d, 1H), 7.56(d, 1H), 7.48(t, 1H), 7.39(d, 1H), 7.27(m, 3H), 6.97(d, 2H), 2.46(s, 6H), 1.38(s, 9H) BD36 8.55(s, 2H), 7.93(m, 3H), 7.82(d, 1H), 7.75(s, 1H), 828.24 828.88 7.72(d, 1H), 7.68(t, 1H), 7.58(d, 1H), 7.28-7.44(m, 8H), 7.16(m, 2H), 1.91(s, 6H), 1.44(s, 9H) BD46 8.55(m, 3H), 8.11(d, 1H), 7.94(d, 2H), 7.83(m, 2H), 679.14 679.65 7.75(s, 1H), 7.68-7.73(m, 3H), 7.47(d, 1H), 7.31- 7.38(m, 4H), 7.16(m, 2H), 6.95(t, 1H) BD65 8.56(d. 2H), 8.15(d, 1H), 7.94(d, 2H), 7.78(d, 1H), 785.15 785.77 7.73(d, 1H), 7.70-7.72(m, 3H), 7.61 (m, 1H), 7.44- 7.53(m, 5H), 7.31-7.35(m, 3H), 7.15(t, 2H), 7.02(d, 2H), 3.81(s, 3H) BD80 8.74(d, 1H), 8.55(d, 2H), 8.15(t, 1H), 8.02(d, 1H), 785.17 785.77 7.94(d, 2H), 7.83(d, 1H), 7.68-7.78(m, 5H), 7.44- 7.52(m, 3H), 7.31-7.35(m, 3H), 7.16(t, 2H), 7.01 (d, 2H), 3.80(s, 3H)

Manufacture of Organic Light-Emitting Device Example 1

As an anode, a glass substrate (product of Corning Inc.) with a 15 n)/cm² (1,200 Å) ITO formed thereon was cut to a size of 50 mm×50 mm×0.7 mm, sonicated with isopropyl alcohol and pure water each for 5 minutes, and cleaned by exposure to ultraviolet rays and ozone for 30 minutes. The resultant structure was mounted on a vacuum deposition apparatus.

2-TNATA was vacuum-deposited on the anode to form a hole injection layer having a thickness of 600 Å, and 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (hereinafter referred to as NPB) was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 300 Å.

Compound BD1 (first compound), Compound ETH66 (second compound), and Compound HTH29 (third compound) were vacuum-deposited on the hole transport layer to form an emission layer having a thickness of 400 Å. In this regard, the amount of Compound BD1 was 10 wt % with respect to the total weight of compounds in the emission layer (100 wt %), and the weight ratio of Compound ETH66 and Compound HTH29 was 3:7.

Compound ETH2 was vacuum-deposited on the emission layer to form a hole blocking layer having a thickness of 50 Å, Alq₃ was vacuum-deposited on the hole blocking layer to form an electron transport layer having a thickness of 300 Å, LiF was vacuum-deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å, and Al was vacuum-deposited thereon to form a cathode having a thickness of 3,000 Å, thereby completing the manufacture of an organic light-emitting device.

Example 2

An organic light-emitting device was manufactured in the same manner as in Example 1, except that, in forming an emission layer, Compound BD5 was used instead of Compound BD1.

Example 3

An organic light-emitting device was manufactured in the same manner as in Example 1, except that, in forming an emission layer, Compound BD27 was used instead of Compound BD1.

Example 4

An organic light-emitting device was manufactured in the same manner as in Example 1, except that, in forming an emission layer, Compound BD65 was used instead of Compound BD1.

Comparative Example 1

An organic light-emitting device was manufactured in the same manner as in Example 1, except that, in forming an emission layer, Compound A was used instead of Compound BD1.

Comparative Example 2

An organic light-emitting device was manufactured in the same manner as in Example 1, except that, in forming an emission layer, Compound B was used instead of Compound BD1.

Example 5

In forming an emission layer, the first to third compounds shown in Table 3 were respectively used as a first compound, a second compound, and a third compound. Unlike in Example 1, DFD2 was additionally used as a fourth compound.

An organic light-emitting device was manufactured in the same manner as in Example 1, except that the amount of the first compound was 10 wt % with respect to the total weight of compounds in the emission layer (100 wt %), the amount of the fourth compound was 0.5 wt % with respect to the total weight of compounds in the emission layer (100 wt %), and the weight ratio of the second compound and the third compound was 3:7.

Example 6

An organic light-emitting device was manufactured in the same manner as in Example 5, except that, in forming an emission layer, Compound BD5 was used instead of Compound BD1.

Example 7

An organic light-emitting device was manufactured in the same manner as in Example 5, except that, in forming an emission layer, Compound BD65 was used instead of Compound BD1.

Comparative Example 3

An organic light-emitting device was manufactured in the same manner as in Example 5, except that, in forming an emission layer, Compound A was used instead of Compound BD1.

Comparative Example 4

An organic light-emitting device was manufactured in the same manner as in Example 5, except that, in forming an emission layer, Compound B was used instead of Compound BD1.

The characteristics of the organic light-emitting devices manufactured according to Examples 1 to 7 and Comparative Examples 1 to 4 were evaluated by measuring the driving voltage (V) at the luminance of 1,000 cd/m², efficiency, maximum emission wavelength (nm), and the like.

The driving voltage (V) at the luminance of 1,000 cd/m², luminescence efficiency (cd/A), maximum emission wavelength (nm), and lifespan (LT₉₅) were measured by using Keithley MU 236 and luminance meter PR650, and results thereof are shown in Tables 2 and 3. In Tables 2 and 3, the lifespan (LT₉₅) is a measure of the time (hr) taken when the luminance reaches 95% of the initial luminance.

TABLE 2 Host Driving Emission Second Third Luminance voltage Efficiency wavelength Lifespan Dopant compound compound (cd/m²) (V) (cd/A) (nm) (LT₉₅) (h) Example 1 BD1 ETH66 HTH29 1000 4.2 20.8 463 80.6 Example 2 BD5 ETH66 HTH29 1000 4.1 21.6 460 77.3 Example 3 BD27 ETH66 HTH29 1000 4.4 20.7 485 90.1 Example 4 BD65 ETH66 HTH29 1000 4.0 24.7 452 82.4 Comparative A ETH66 HTH29 1000 4.4 18.7 482 64.2 Example 1 Comparative B ETH66 HTH29 1000 4.3 17.5 480 54.9 Example 2

Referring to Table 2, it is confirmed that the organic light-emitting devices manufactured according to Examples 1 to 4 show excellent results compared to those of the organic light-emitting devices manufactured according to Comparative Examples 1 and 2.

TABLE 3 Dopant Host Driving Emission First Fourth Second Third Luminance voltage Efficiency wavelength Lifespan compound compound compound compound (cd/m²) (V) (cd/A) (nm) (LT₉₅) (h) Example 5 BD1 DFD2 ETH66 HTH29 1000 4.6 19.1 461 54.3 Example 6 BD5 DFD2 ETH66 HTH29 1000 4.4 18.9 461 56.1 Example 7 BD65 DFD2 ETH66 HTH29 1000 4.5 19.7 461 55.8 Comparative A DFD2 ETH66 HTH29 1000 4.7 16.7 461 49.1 Example 3 Comparative B DFD2 ETH66 HTH29 1000 4.6 17.6 461 47.1 Example 4

Referring to Table 3, it is confirmed that the organic light-emitting devices manufactured according to Examples 5 to 7 show excellent results compared to those of the organic light-emitting devices manufactured according to Comparative Examples 3 and 4.

A light-emitting device according to an embodiment has excellent efficiency and lifespan.

Embodiments have been disclosed herein, and although terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent by one of ordinary skill in the art, features, characteristics, and/or elements described in connection with an embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the disclosure as set forth in the following claims. 

What is claimed is:
 1. A light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and an interlayer disposed between the first electrode and the second electrode, wherein the interlayer includes an emission layer the emission layer comprises: a first compound which is an organometallic compound represented by Formula 1; and a second compound comprising at least one π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group, a third compound represented by Formula 11, a fourth compound capable of emitting delayed fluorescence, or a combination thereof, and the first compound, the second compound, the third compound, and the fourth compound are different from one another:

wherein in Formula 1, M₁ is a transition metal, ring A₁ to ring A₄ are each independently a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, L₁ and L₂ are each independently a single bond, *—O—*′, *—S—*′, *—C(R₅)(R₆)—*′, *—C(R₅)=*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, or *—Ge(R₅)(R₆)—*′, L₃ is *—N(R₇)—*′, L₄ is *—N(R₈)—*, a1 and a2 are each independently 0, 1, 2, or 3, one of a1 and a2 is 0, when a1 is 0, ring A₁ and ring A₂ are not linked to each other, when a2 is 0, ring A₂ and ring A₃ are not linked to each other, a3 and a4 are each independently 1, 2, or 3, Y₁ to Y₃ are each independently a carbon atom (C) or a nitrogen atom (N), Y₄ is a nitrogen atom (N), B₁ to B₄ are each independently a chemical bond, *—O—*′, or *—S—*′, R₁ to R₈ are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_(10a), a C₈-C₆₀ monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_(10a), —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), or —P(═S)(Q₁)(Q₂), two neighboring substituents among R₁ to R₈ are optionally linked to each other to form a C₅-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), b1 to b4 are each independently an integer from 1 to 5, and * and *′ each indicate a binding site to a neighboring atom,

wherein in Formula 11, A₅ is O, S, N(R″₁₂), or C(R″₁₃)(R″₁₄), m and n are each independently an integer from 0 to 4, R″₆ to R″₁₄ are each independently the same as described in connection with R₁ in Formula 1, and b″6 to b″11 are each independently an integer from 0 to 4, and R_(10a) is: deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or a combination thereof; a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, or a C₆-C₆₀ arylthio group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or a combination thereof; or —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; or a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, or a combination thereof.
 2. The light-emitting device of claim 1, wherein M₁ is platinum (Pt), palladium (Pd), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), gold (Au), rhodium (Rh), iridium (Ir), ruthenium (Ru), rhenium (Re), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm).
 3. The light-emitting device of claim 1, wherein ring A₁ to ring A₃ are each independently a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, an azulene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, an indenopyrimidine group, an indolopyrimidine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a benzosilolopyrimidine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a 2,3-dihydroimidazole group, a triazole group, a 2,3-dihydrotriazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a pyrazolopyridine group, a furopyrazole group, a thienopyrazole group, a benzimidazole group, a 2,3-dihydrobenzimidazole group, an imidazopyridine group, a 2,3-dihydroimidazopyridine group, a furoimidazole group, a thienoimidazole group, an imidazopyrimidine group, a 2,3-dihydroimidazopyrimidine group, an imidazopyrazine group, a 2,3-dihydroimidazopyrazine group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, or a 5,6,7,8-tetrahydroquinoline group.
 4. The light-emitting device of claim 1, wherein ring A₄ is an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, an indenopyrimidine group, an indolopyrimidine group, a benzofuropyrimidine group, a benzothienopyrimidine group, a benzosilolopyrimidine group, a dihydropyridine group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, or a quinazoline group.
 5. The light-emitting device of claim 1, wherein ring A₄ is an indenopyridine group, an indolopyridine group, a benzofuropyridine group, a benzothienopyridine group, a benzosilolopyridine group, a dihydropyridine group, or a pyridine group, and ring A₁ to ring A₃ are each independently a group represented by one of Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25):

wherein in Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25), Y₁₅ is a carbon atom (C) or a nitrogen atom (N), X₂₁ is N or C(R₂₁), X₂₂ is N or C(R₂₂), X₂₃ is N or C(R₂₃), X₂₄ is N or C(R₂₄), X₂₅ is N or C(R₂₅), X₂₆ is N or C(R₂₆), X₂₇ is N or C(R₂₇), X₂₈ is N or C(R₂₈), X₂₉ is C(R_(29a))(R_(29b)), Si(R_(29a))(R_(29b)), N(R₂₉), O, or S, X₃₀ is C(R_(30a))(R_(30b)), Si(R_(30a))(R_(30b)), N(R₃₀), O, or S, R₂₁ to R₃₀ and R_(29a) to R_(30b) are each independently the same as described in connection with R₁ in Formula 1, * indicates a binding site to B₁, B₂, or B₃, and *′ and *″ each indicate a binding site to a neighboring atom.
 6. The light-emitting device of claim 1, wherein a1 in Formula 1 is 0, ring A₄ is a group represented by one of Formulae 2-2(1) to 2-2(9), and R₇ and R₈ are each independently a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_(10a):

wherein, in Formulae 2-2(1) to 2-2(9) Y₁₅ is a nitrogen atom (N), X₂₁ is N or C(R₂₁), X₂₂ is N or C(R₂₂), X₂₃ is N or C(R₂₃), X₂₄ is N or C(R₂₄), X₂₅ is N or C(R₂₅), X₂₆ is N or C(R₂₆), X₂₇ is N or C(R₂₇), X₂₈ is N or C(R₂₈), X₂₉ is C(R_(29a))(R_(29b)), Si(R_(29a))(R_(29b)), N(R₂₉), O, or S, X₃₀ is C(R_(30a))(R_(30b)), Si(R_(30a))(R_(30b)), N(R₃₀), O, Or S, R₂₁ to R₃₀ and R_(29a) to R_(30b) are each independently the same as described in connection with R₁ in Formula 1, * indicates a binding site to B₄, and *′ and *″ each indicate a binding site to a neighboring atom.
 7. The light-emitting device of claim 1, wherein the organometallic compound represented by Formula 1 is represented by Formula 2:

wherein in Formula 2, M₁, ring A₁ to ring A₃, L₁, L₂, a1, a2, Y₁ to Y₃, B₁ to B₄, R₁ to R₄, and b1 to b3 are the same as described in connection with Formula 1, R′₇ and R′₈ are each independently the same as described in connection with R₁ in Formula 1, and b7 and b8 are each independently an integer from 1 to
 4. 8. The light-emitting device of claim 7, wherein ring A₁ to ring A₃ in Formula 2 are each independently a group represented by one of Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25):

wherein in Formulae 2-1(1) to 2-1(35) and 2-2(1) to 2-2(25), Y₁₅ is a carbon atom (C) or a nitrogen atom (N), X₂₁ is N or C(R₂₁), X₂₂ is N or C(R₂₂), X₂₃ is N or C(R₂₃), X₂₄ is N or C(R₂₄), X₂₅ is N or C(R₂₅), X₂₆ is N or C(R₂₆), X₂₇ is N or C(R₂₇), X₂₈ is N or C(R₂₈), X₂₉ is C(R_(29a))(R_(29b)), Si(R_(29a))(R_(29b)), N(R₂₉), O, or S, X₃₀ is C(R_(30a))(R_(30b)), Si(R_(30a))(R_(30b)), N(R₃₀), O, or S, R₂₁ to R₃₀ and R_(29a) to R_(30b) are each independently the same as described in connection with R₁ in Formula 1, * indicates a binding site to B₁, B₂, or B₃, and *′ and *″ each indicate a binding site to a neighboring atom.
 9. The light-emitting device of claim 1, wherein the first compound represented by Formula 1 is one selected from Compounds BD1 to BD91:

wherein in Compounds BD1 to BD91, D₅ indicates that five deuterium atoms are substituted at the indicated moiety.
 10. The light-emitting device of claim 1, wherein the first electrode is an anode, the second electrode is a cathode, and the interlayer further comprises: a hole transport region disposed between the first electrode and the emission layer and comprising a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or a combination thereof; and/or an electron transport region disposed between the second electrode and the emission layer and comprising a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.
 11. The light-emitting device of claim 1, wherein the emission layer comprises the fourth compound, and a weight ratio of the first compound to the fourth compound is in a range of about 10:0.1 to about 10:1.0.
 12. The light-emitting device of claim 1, wherein the second compound comprises a compound represented by Formula 10:

wherein in Formula 10, ring Ar₃ to ring Ar₅ are each independently a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, E is N or C(R″₆), F is N or C(R″₇), G is N or C(R″₈), R″₃ to R″₈ are each independently the same as described in connection with R₁ in Formula 1, and b″3 to b″5 are each independently an integer from 1 to
 5. 13. The light-emitting device of claim 12, wherein the second compound represented by Formula 10 is one selected from Compounds ETH1 to ETH84:

wherein in Compounds ETH1 to ETH84, D₄ indicates that four deuterium atoms are substituted at the indicated moiety.
 14. The light-emitting device of claim 1, wherein the emission layer comprises the second compound and the third compound, and a weight ratio of the second compound to the third compound is in a range of about 3:7 to about 7:3.
 15. The light-emitting device of claim 1, wherein the third compound represented by Formula 11 is one selected from Compounds HTH1 to HTH52:

wherein in Compounds HTH1 to HTH52, D₄ indicates that four deuterium atoms are substituted at the indicated moiety.
 16. The light-emitting device of claim 1, wherein the fourth compound is represented by Formula 12:

wherein in Formula 12, A₆ is O, S, N(R″₂₄), or C(R″₂₅)(R″₂₆), A₇ is O, S, N(R″₂₇), or C(R″₂₈)(R″₂₉), A₈ is O, S, N(R″₃₀), or C(R″₃₁)(R″₃₂), A₉ is O, S, N(R″₃₃), or C(R″₃₄)(R″₃₅), R″₂₀ to R″₃₅ are each independently the same as described in connection with R₁ in Formula 1, b″20 and b″21 are each independently an integer from 0 to 3, and b″22 and b″23 are each independently an integer from 0 to
 4. 17. The light-emitting device of claim 16, wherein the fourth compound represented by Formula 12 is one selected from Compounds DFD1 to DFD12:

wherein in Compounds DFD1 to DFD12, D₅ indicates that five deuterium atoms are substituted at the indicated moiety.
 18. An electronic apparatus comprising the light-emitting device of claim
 1. 19. The electronic apparatus of claim 18, further comprising a thin-film transistor, wherein the thin-film transistor comprises a source electrode and a drain electrode, and the first electrode of the light-emitting device is electrically connected to at least one of the source electrode and the drain electrode of the thin-film transistor.
 20. An organometallic compound represented by Formula 1:

wherein in Formula 1, M₁ is a transition metal, ring A₁ to ring A₄ are each independently a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, L₁ and L₂ are each independently a single bond, *—O—*′, *—S—*′, *—C(R₅)(R₆)—*′, *—C(R₅)=*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—B(R₅)—*′, *—N(R₅)—*′, *—P(R₅)—*′, *—Si(R₅)(R₆)—*′, *—P(R₅)(R₆)—*′, or *—Ge(R₅)(R₆)—*′, L₃ is *—N(R₇)—*′, L₄ is *—N(R₈)—*, a1 and a2 are each independently 0, 1, 2, or 3, one of a1 and a2 is 0, when a1 is 0, ring A₁ and ring A₂ are not linked to each other, when a2 is 0, ring A₂ and ring A₃ are not linked to each other, a3 and a4 are each independently 1, 2, or 3, Y₁ to Y₃ are each independently a carbon atom (C) or a nitrogen atom (N), Y₄ is a nitrogen atom (N), B₁ to B₄ are each independently a chemical bond, *—O—*′, or *—S—*′, R₁ to R₈ are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_(10a), a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_(10a), a C₈-C₆₀ monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_(10a), —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), or —P(═S)(Q₁)(Q₂), two neighboring substituents among R₁ to R₈ are optionally linked to each other to form a C₅-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), b1 to b4 are each independently an integer from 1 to 5, and * and *′ each indicate a binding site to a neighboring atom, and R_(10a) is: deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or a combination thereof; a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, or a C₆-C₆₀ arylthio group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or a combination thereof; or —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; or a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, or a combination thereof. 